Transplant increases survival for patients with kidney failure due to sickle cell disease
Patients with sickle cell disease-related kidney failure experienced similar reductions in mortality following transplantation as those whose kidney failure stemmed from other causes, according to researchers from Johns Hopkins.
Despite this observed benefit, study results also indicated patients with sickle cell disease were less likely to receive a transplant than patients with other kidney failure etiologies.
“Previously, some providers who relied upon older data expressed concerns that transplantation may be rather futile in the sickle cell population given their relatively high mortality rate after transplantation,” Sunjae Bae, KMD, PhD, said in a related press release. “On the other hand, the sickle cell population also shows extremely high mortality while on dialysis. Therefore, if their post-transplant mortality is still sufficiently lower than their dialysis mortality, kidney transplantation could be a preferable treatment option in the sickle cell population.”
To investigate, researchers used national data related to all adults with kidney failure who began maintenance hemodialysis or who were added to the transplant waitlist between 1998 and 2017.
“First, we examined mortality rates and measured decreases in mortality associated with transplantation in patients with kidney failure due to sickle cell disease [vs.] other etiologies,” the researchers wrote of the two primary objectives of the study. “Second, we compared access to transplantation between the sickle cell and non-sickle cell populations, from dialysis initiation, to transplant waitlist registration, to receipt of a kidney transplant.”
When comparing transplant recipients to a cohort of matched waitlisted controls, researchers found transplant significantly decreased mortality for all recipients, despite the cause of kidney failure (absolute risk difference at 10 years was 20.3 percentage points for patients with sickle cell disease vs. 19.8 percentage points for patients with other etiologies).
“Although transplant recipients from the sickle cell group experienced higher post-transplant mortality compared with recipients from the controls (10 year, 50% [vs.] 32%), the amount of the decrease in mortality associated with transplantation was similar in both groups,” the researchers wrote.
Still, results showed patients in the sickle cell group were 38% less likely to receive kidney transplantation than patients whose kidney failure was due to other causes (sub-distribution hazard ratio = 0.73). Furthermore, the researchers emphasized that patients with sickle cell disease who were already waitlisted experienced increased disparities (sub-distribution HR= 0.62).
“The worse access to kidney transplantation in the sickle cell group was the most pronounced in the candidates who were waitlisted,” Bae and colleagues wrote. “This was unexpected because having sickle cell disease as the primary cause of kidney failure has never been explicitly considered in the kidney allocation criteria and, therefore, should not affect the chances of waitlisted candidates receiving a transplant.”
In a related patient voice, Sasha Couch addressed the “health disparities across racial and socioeconomic lines” that she has been aware of since childhood, growing up with family members who had such comorbidities as diabetes, hypertension, heart disease and sickle cell disease.
“When you live with a disease that can cause other issues, you live in perpetual fear,” she wrote. “Sickle cell disease is unique in that it almost exclusively affects Black Americans and, more recently, smaller numbers of Hispanic Americans and others. Since acquiring diabetes at the age of 12 [years], I have always gone to the doctor regularly — although distrust in the medical complex permeates the Black community. As an adult, I understand why. From the Tuskegee experiment to Black maternal mortality rates today, such distrust is warranted.”
Due to these biases in health care, Couch suggested the “fear” Black patients experience is not only related to developing another disease, but not receiving adequate treatment.
She acknowledged that, due to her socioeconomic position, she was able to access “exceptional medical care” and find a transplant match; this, she argued, is not possible for many.
“For me, access to information and proper care from health care providers makes me feel ‘seen’ and better prepared for the challenges of life with a disease,” she wrote. “I want that same feeling for everyone with sickle cell disease and kidney disease.”
According to Tanjala S. Purnell, PhD, MPH, co-author on the study, it is imperative that those in nephrology improve access to transplantation for patients with sickle cell disease.
“Our research study, which uses our national registry of all patients, demonstrates better survival with transplant for these patients,” she said in the press release. “We must eliminate disparities in access to this life-saving procedure.”